It looks like you have a lot of members with the ability to moderate content, which is an administrative permission. All of your Talent Academy circles include the permission to moderate content in the Talent Academy forums (which is an Administrative permission), and those all add up to about 32. If you really want those users to moderate content, you'll need to change to a plan that accommodates a lot more Admins.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .